Scientists claim chemical recycling breakthrough for polystyrene


A team of scientists from both sides of the Atlantic have modelled a technique they say could become the first viable way of recycling polystyrene.

Chemical engineers from the University of Bath and Worcester Polytechnic Institute in Massachusetts say pyrolysis could break the material, commonly used in food and drink containers, into parts that can be reformed.


Less than 5 per cent of polystyrene is currently recycled, according to the scientists, who believe this could be increased to 60 per cent using their methods.

Pyrolysis involves exposing material to temperatures of more than 450 degrees in an oxygen-free chamber to create monomers that can then be purified and reconstituted into virgin polystyrene.

Dr Bernardo Castro-Dominguez, senior lecturer in chemical engineering at the University of Bath, said cost and energy efficient ways to break plastics down to their primary building blocks were “urgently needed”.

Michael Timko, professor of chemical engineering at Worcester Polytechnic Institute, added: “Our analysis finds polystyrene to be an ideal candidate for a chemical recycling process.

“In terms of emissions, investing in this process has the potential to be equivalent to simple measures such as energy conservation in terms of the amount of emissions reduction that can be achieved for a given investment.”

The research paper, titled Thermodynamic and Economic Analysis of a Deployable and Scalable Process to Recover Monomer-Grade Styrene from Waste Polystyrene, was published in the Chemical Engineering Journal.